Plastic pipe tapering device

ABSTRACT

A rotary tool for concurrently forming a circumferential taper of desired angulation on an end portion of a length of plastic pipe and facing the end extremity of said portion to be normal to the longitudinal axis of the pipe.

United States Patent Stephen Dackow 808 E. Ocean Front, Balboa. Calif.92661 870,583

Nov. 5, 1969 July 27, 1971 Inventor Appl. No. Filed Patented PLASTICPIPE TAPERING DEVICE 10 Claims, 8 Drawing Figs.

u.s. c|. 82/4 C, 77/73 Int. Cl. B23b 5/16 Field ofSearch 82/4.8 C; 77/73[56] References Cited UNITED STATES PATENTS 1,572,924 2/1926 Hand et al.532/4 C 2,470,392 5/1949 Gassmann 77/73 3,l67,982 2/l965 Sherwood 82/4 CPrimary Examiner- Leonidas Vlachos A!!orneyWilliam C. Babcock ABSTRACT:A rotary tool for concurrently forming a circumferential taper ofdesired angulation on an end portion of a length of plastic pipe andfacing the end extremity of said portion to be normal to thelongitudinal axis of the pipe.

PATENTEU JUL27 l9?! 1 O7 FIG.I 5 2 INVENTOR. STEPHEN finc 1511M QMArron/var .RQLSHQRIRE .TAPER N ICE BACKGROUND OF THE INVENTION 1. Fieldof the Invention A rotary tool for concurrently tapering and facing theend portions of plastic pipe. I

2. Description of the Prior Art Plasticpipe formed from a material suchas unplasticized polyvinyl chloride has recently been introduced inwhich lengths of the pipe are joined together end to'end by slip fits.ln joining such pipe together, an end portion of a first length thereofis longitudinally forced into the bulged end portion of a second lengththereof to sealingly engage a resilient ring contained therein. Eachlength of pipe as furnished by a manufacturer has a taper formed on'afirst end thereof to effect initial slidable engagement with thesealingring contained in the bulged end of a second length of the pipe.However, when such pipe is being installed a length thereof mustoccasionally be cut to effect a connection, with the taper formed on thelength of pipe by the manufacturer being removed therefrom.

Until thedevelopment of the present invention, no simple easily usedtool has been available to taper and face a cut end portion of plasticpipe. The present invention provides a tool to taper and face a cut endportion of plastic pipe to permit the i cut end portion to be slidablyand sealingly engaged by a sealing ring in the bulged end portion of asecond length of the pipe.

SUMMARY OF THE'INVENTION A tool that includes a rigid body that may beeither hand or power rotated, with the body supporting a cylindricalmandrel that slidably and rotatably engages the interior of an endportion of plastic pipe, and a cutter bar removably mounted in alongitudinal position on the body and extending over the mandrel. Whenthe body, mandrel and cutter bar are concurrently rotated in engagementwith an end portion of plastic pipe. the end portion is concurrentlyfaced and has a circumferential taper of desired angulation formedthereon.

BRIEF DESCRIPTION OFTHE DRAWINGS portion of a length of plastic pipe;

FIG. 3 is the same cross-sectional view as shown in FIG. 2

but after the end portion of pipe has been tapered and faced;

' F IG 4 is a-front elevational view of the tool;

-FIG. 5 is a transverse cross-sectional view of the tool;

FIG. 6 is an enlarged side elevational view of a portion of the cutterbar in engagement with an end portion of plastic pipe, and after thelatter has been tapered and faced;

FIG. 7 is a transverse cross-sectional view of the cutter bar taken onthe line 7-7 thereof in Figure 6; and

FIG. 8 is a perspective view of the tool mounted on a poweractuatedunit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A tool A for forming a taper ona cut end portion of plastic pipe B is shown in FIG. 1. The tool Aconcurrently with forming a taper on the pipe B also faces the end ofthe pipe adjacent to the taper to be normal to the longitudinal axis Cof the pipe.

Tool A includes a rigid cylindrical body 10 that has a diametersubstantially greater than the external cross-sectional diameter of thepipe B that is to have a taper formed on an end portion thereof. Acylindrical mandrel 12 projects forwarding from a first end, of body 10and is longitudinally aligned therewith. Body 10 and mandrell2tcooperate at their junction to define an annulus shaped body shoulder14. The mandrel 12 is of such cross section as to slidably and rotatablyengage the interior surface 16 of the pipe B. a

A longitudinal slot 18 of square or rectangular cross section is formedin body 10 and extends the length thereof. Slot 18 is removably engagedby a cutter bar I); A number of longitudinally spaced transverse tappedbores 20 areformed in body 10, and are in communication with slot 18.The tapped bores 20 are engaged by screws 22. Screws 22 when tightenedbear against cutter bar D, and serve'to removably hold the cutter bar ina desired longitudinal position in slot 18.

Cutter bar D on a first end portion24 thereof has first and secondlongitudinally extending faces 26 and 28 that intersect 'to define firstand second cutting edges 30 and 32 that are preferably connected'bya'third curved cutting edge 34 as shown in Figure 6. First and secondfaces 26 and 28 asmay best be seen in FIG. 7 sustain an angle of lessthan 90 therebetween.

The forward extremity 30a of edge 30 is spaced outwardly from theexternal surface 36 of mandrel 12 a distance greater than the thicknessof the'wall of pipe B that is to have a taper formed on an end portionthereof. Such spacing is required to permit easy initial entry of an endportion of the pipe B into the space defined between the cutting edge 30and mandrel surface 36.

The cutter bar D is held inslot 18 by screws 22 in such a position thatsecond cutting edge 32 is slightly forwardly disposed from body shoulder14. If the tool A is to be hand rotated to form a taper on an endportion of pipe B, the external surface of body 10 preferably has knurls38 formed thereon. The knurls 38 tend to prevent rotational slippage ofthe body 10 relative to the hand of the user (not shown) that grips thebody.

Body .10 may have an elongate recess 40 that extends inwardly from asecond end 42 thereof to permit thebody to be rotated by an engagingpower driven member 44 of an electric drill 46. A sleeve of hard metal48 is disposed in recess 40, if the body 10 is formed from a lightweightrelatively soft metal such as aluminum or the like. The recess engagedby the member 44 is preferably of noncircular transverse cross section.Tool A may-also be gripped in a chuck 50' and rotated by an electricmotor 52 as shown in Figure 8.

Irrespective of how the tool A is rotated, the method of forming a taper54 and faced edge 56 on an end portion of the pipe B is the same. An endportion ofthe pipe B is caused to slidably engage mandrel 12, with thetool A thereafter rotated. The rotating first cuttingedge 30 forms thetaper 56 on the pipe B as the pipe is advanced towards the tool. As theforming of the taper 56 is being completed the rotating second cuttingedge 32 forms the faced edge 54' on the end portion of the pipe. Thethird cutting edge 34 forms a curved surface 54 on the pipe thatsmoothly connects the taper 50 to the faced edge 52.

Cutter bar D is preferably formed with a second end portion 24' that isidentical with first portion 24, to permit the second portion 24 to beused after thefirst portion 24 becomes dull from use. Second portion 24'is used for forming a taper and facing the end of a length of plasticpipe, by reversing the position of the cutter bar D in slot 18. Toprotect the projecting forward portion 24 from damage by inadvertentcontact with a hard object, a protective cylindrical shell 58 may befrictionally mounted on the external surface of body 10 and extendforwardly therefrom over mandrel l2.

lclaim: v

l. A device for use in concurrently forming a cylindrical taperedsurface on an end portion of a plastic pipe and facing said end portionto have a circumferential end extremity that is normal to thelongitudinal axis of said pipe, said device including:

a. an assembly that includes a rotatable elongate body that has alongitudinal slot that extends the length thereof, said body having atransverse diameter substantially greater than the external diameter ofsaid pipe, and a longitudinally aligned cylindrical mandrel that extendsforwardly from a first end ofsaid body, said mandrel and body at theirjunction defining a circumferentially extending body shoulder, and saidmandrel of such transverse cross section as to slidably and rotatablyengage said pipe when said body is rotated relative to said pipe;

b. a cutter bar removably positioned in said slot with a first endportion of said bar projecting forwardly from said body and spaced fromsaid mandrel, said first end portion defining first and second cuttingedges, said first cutting edge extending longitudinally on said firstportion, said first cutting edge having the forward extremity thereofspaced outwardly from said mandrel a distance greater than the maximumwall thickness of pipe on which said device will be used, said firstcutting edge tapering inwardly towards said mandrel at an angle at whichit is desired to form said tapered surface. Said first cutting edge onthe rearward end thereof developing into said second cutting edge; and

c. first means for removably holding said cutter bar in said slot withsaid second cutting edge disposed slightly forwardly from said bodyshoulder, and said assembly and cutter bar when rotated concurrentlyrelative to said end portion of said pipe and moved longitudinallyrelative thereto forming said tapered surface and end extremity by saidfirst and second cutting edges being in pressure cutting contact withsaid end portion.

2. A device as defined in claim 1 in which said first cutting edge isdefined by first and second longitudinal intersecting surfaces on saidfirst end portion, said first and second surfaces sustaining an angle ofless than 90 therebetween, with said first surface radially alignedrelative to said mandrel, and said second surface sloping upwardly andaway from said mandrel.

3. A device as defined in claim 1 in which said slot and cutter bar areof rectangular transverse cross sections, and said first means are aplurality of screws that engage tapped bores formed in said body thatcommunicate with said slot, with said screws when tightened in saidbores pressure con- 5. A device as defined in claim 4 in which saidsecond means is a longitudinally centered recess of noncirculartransverse cross section that extends into said body from said secondend thereof.

6. A device as defined in claim 1 in which said cutter bar includes asecond end portion identical to said first end portion, and said secondend portion capable of being used to form said tapered surface and endextremity on said pipe when said cutter bar is so disposed in said slotthat said second portion extends forwardly over said mandrel.

7. A device as defined in claim 1 in which at least a portion of saidsecond edge is substantially normal to said mandrel.

8. A device as defined in claim 7 in which said first and second edgesmerge into a curved third cutting edge formed in said cutter bar andsituated between said first and second edges.

9. A device as defined in claim 1 in which said body is formed with aknurled exterior surface that may be grasped manually to facilitate therotation of said body, mandrel and cutter bar relative to said pipe.

10. A device as defined in claim 1 which in addition includes:

d. a cylindrical shell that frictionally engages the exterior surface ofsaid body and extends over said first end portion of said cutter bar toprevent damage to said cutter bar by inadvertent contact with a hardobject.

1. A device for use in concurrently forming a cylindrical taperedsurface on aN end portion of a plastic pipe and facing said end portionto have a circumferential end extremity that is normal to thelongitudinal axis of said pipe, said device including: a. an assemblythat includes a rotatable elongate body that has a longitudinal slotthat extends the length thereof, said body having a transverse diametersubstantially greater than the external diameter of said pipe, and alongitudinally aligned cylindrical mandrel that extends forwardly from afirst end of said body, said mandrel and body at their junction defininga circumferentially extending body shoulder, and said mandrel of suchtransverse cross section as to slidably and rotatably engage said pipewhen said body is rotated relative to said pipe; b. a cutter barremovably positioned in said slot with a first end portion of said barprojecting forwardly from said body and spaced from said mandrel, saidfirst end portion defining first and second cutting edges, said firstcutting edge extending longitudinally on said first portion, said firstcutting edge having the forward extremity thereof spaced outwardly fromsaid mandrel a distance greater than the maximum wall thickness of pipeon which said device will be used, said first cutting edge taperinginwardly towards said mandrel at an angle at which it is desired to formsaid tapered surface. Said first cutting edge on the rearward endthereof developing into said second cutting edge; and c. first means forremovably holding said cutter bar in said slot with said second cuttingedge disposed slightly forwardly from said body shoulder, and saidassembly and cutter bar when rotated concurrently relative to said endportion of said pipe and moved longitudinally relative thereto formingsaid tapered surface and end extremity by said first and second cuttingedges being in pressure cutting contact with said end portion.
 2. Adevice as defined in claim 1 in which said first cutting edge is definedby first and second longitudinal intersecting surfaces on said first endportion, said first and second surfaces sustaining an angle of less than90* therebetween, with said first surface radially aligned relative tosaid mandrel, and said second surface sloping upwardly and away fromsaid mandrel.
 3. A device as defined in claim 1 in which said slot andcutter bar are of rectangular transverse cross sections, and said firstmeans are a plurality of screws that engage tapped bores formed in saidbody that communicate with said slot, with said screws when tightened insaid bores pressure contacting said cutter bar and frictionally holdingsaid cutter bar in said slot.
 4. A device as defined in claim 1 which,in addition, includes: second engageable means on a second end of saidbody for concurrently rotating said body mandrel and cutter bar whensaid second engageable means are engaged by a power driven rotatableengaging member.
 5. A device as defined in claim 4 in which said secondmeans is a longitudinally centered recess of noncircular transversecross section that extends into said body from said second end thereof.6. A device as defined in claim 1 in which said cutter bar includes asecond end portion identical to said first end portion, and said secondend portion capable of being used to form said tapered surface and endextremity on said pipe when said cutter bar is so disposed in said slotthat said second portion extends forwardly over said mandrel.
 7. Adevice as defined in claim 1 in which at least a portion of said secondedge is substantially normal to said mandrel.
 8. A device as defined inclaim 7 in which said first and second edges merge into a curved thirdcutting edge formed in said cutter bar and situated between said firstand second edges.
 9. A device as defined in claim 1 in which said bodyis formed with a knurled exterior surface that may be grasped manuallyto facilitate the rotation of said body, mandrel and cutter bar relativeto said pipe.
 10. A device as defined in claIm 1 which in additionincludes: d. a cylindrical shell that frictionally engages the exteriorsurface of said body and extends over said first end portion of saidcutter bar to prevent damage to said cutter bar by inadvertent contactwith a hard object.